Well, it was as bad as expected

[Hedges]

Dang! Now I'm going to have to change my entire design to use cement studs. No, I'm going with a double layer of solid concrete walls with 2" rigid foam between them.

Half an inch of plaster covering all sheetmetal surface (it's used to make fire resistant safes because absorbs heat as it decomposes), and use blown-in asbestos insulation.

Concrete is not the strongest stuff in a fire:

Speeding tanker crash leads to fire, freeway collapse

Speeding tanker crash leads to fire, freeway collapse

www.eastbaytimes.com

(But only a problem if your house ends up like the twin towers, either gasoline truck or plane full of aviation fuel crashes into it.)

 

[HRTKD]

Half an inch of plaster covering all sheetmetal surface (it's used to make fire resistant safes because absorbs heat as it decomposes), and use blown-in asbestos insulation.

Concrete is not the strongest stuff in a fire:

Speeding tanker crash leads to fire, freeway collapse

Speeding tanker crash leads to fire, freeway collapse

www.eastbaytimes.com

(But only a problem if your house ends up like the twin towers, either gasoline truck or plane full of aviation fuel crashes into it.)

You're really pissing in my Cheerios this morning. LOL!

 

[jvbutter01]

This excerpt is from the webpage titled Effective Insulation R-Values in Steel vs. Wood Framing.

Well holly molly... I didn't see that. would never have guessed with all the stick built homes out there... thanks for the education.

 

[jvbutter01]

A 2x stud is under 2" thick, about 1.5" (which helps your insulation). 16" on center, you have 14.5" fiberglass batt insulation, 1.5" wood.
If thermal conductivity of wood is 10 times that of the fiberglass insulation, half you heat would escape through each.

According to the math I just did, almost half the heat is lost through the 1.5" wide space between insulation batts.
It is that inefficient. Or, fiberglass insulation is that good, approaches point of diminishing returns.
Since OP wanted to avoid losing heat through the walls, I pointed out that a thermal break to block heat through the studs could insulating value. Polyurethane is 4x better than wood, so a 1" layer over a 4" thick wall would cut loss through wood in half, reducing loss through wall (if no windows) by 25%.

@Hedges I am corrected. Thanks for the details, as said above to @HRTKD Did not know it was such an energy loss. You are correct.

yes steel studs are more fire danger, they will bend when getting hot vs the time it takes for a stud to catch fire, and burn enough to collapse.

 

[HRTKD]

In my opinion, if your studs are on fire, it's pretty much a total loss. Even with the metal studs, if they're melting, it's game over. So to me, it's a wash either way.

My RV trailer has aluminum studs in the walls. I can find the studs in the winter by running my hand on the inside wall. Cold spot = stud.

 

[Deleted-User]

In my opinion, if your studs are on fire, it's pretty much a total loss. Even with the metal studs, if they're melting, it's game over. So to me, it's a wash either way.

My RV trailer has aluminum studs in the walls. I can find the studs in the winter by running my hand on the inside wall. Cold spot = stud.

A new technique I noticed this fire season in NorCal...folks wrapping their houses in reflective mylar, a radiant barrier, done in time as the fire approached. Made perfect sense to me, since emergency 'blankets' are similar, and much of the flammability of wood structures is associated with the pre-heating of the structure during the passing inferno.

Firezat - Wildfire Protection Services- USA, Canada, Australia

firezat.com

Does anyone here have personal experience with SIP panel construction, and can vouch for durability/efficiency?

 

[Picasso]

Sip's are great till rodents get into the foam. Foam can be flammable. All urban wild fire interface sites have to use none combustible products now in CA. So hardie planks and the like.

The foil wrapping is Cal-fire protection teams not the home owners.

Cost for me to run grid to my house was $325,000.00

 

[Pickuptrck]

where do you get data on 2x4 boards loosing 1/2 the thermal heat of 16" on center walls? Wood is an insulator. If you have good insulation between the studs, you wont have 1/2 heat loss?

Yes doing an extra layer on your external wall is best, has anyone heard of double pane windows, or triple?

I left that one. I've watched a bunch of videos by Matt Risinger and living in europe for 8 years, the passivhouse (spelling varies by country), I'm sold on 2x6s, spray foam in cavities and 4" thick exterior foam. My budget absolutely won't cover spray foam, but seeing houses under construction here is maddening when compared to our US minimum standards. I'm not a fan of wood anyway, most castles here only went into ruins when the 1 ft timber floor or roof beams failed. Walls are still undeniably solid after 200+ years... and stone

 

[Deleted-User]

Sip's are great till rodents get into the foam. Foam can be flammable. All urban wild fire interface sites have to use none combustible products now in CA. So hardie planks and the like.

The foil wrapping is Cal-fire protection teams not the home owners.

Cost for me to run grid to my house was $325,000.00

Did a bit of digging, and somewhat ironically, stumbled upon one of those rare confluences/two birds,one stone: A polished steel SIP home:

PictureTrail: Online Photo Sharing, Social Network, Image Hosting, Online Photo Albums

PictureTrail provides online photo sharing, personal homepages and image hosting.

www.picturetrail.com

This is like a cloaked home, pre-wrapped for fire and rodent protection.

 

[JoeHam]

Does anyone here have personal experience with SIP panel construction, and can vouch for durability/efficiency?

I built our house with steel stud structure/styrofoam SIP.

Exterior walls are about 9 inches thick and the ceiling about 14 inches thick.

Exterior covered with OSB, then basic wrap. The OSB was to make it easier to vinyl side without having to find the steel studs. Conventional roof. Drywall interior.

We face the water on the south side of the house and have a considerable amount of windows there.

On a sunny day in February I will turn off the heat first thing in the morning and the house will passively heat well into the 70’s fahrenheit while it is single digit temperatures outside.

I expect the house will outlive me by a considerable margin ?

 

[Pickuptrck]

I don’t see any copper there. Wires, lugs etc.

Will your panel racking be just landscape timbers?

Edit: I just saw that you left those out for now. Focused on the tree (spreadsheet) and missed the forest

More coffee please

Looking forward to seeing pictures of the racking you build.

Also wish we had met when I tried unsuccessfully to get a group buy of panels together this summer from SanTanSolar to Ohio.

I haven't heard of using motorcycle crates as suggested, that would be an awesome setup. Definitely want to build a DIY solar tracker. I know more panels will solve the loss, though using something at 60% contradicts my Ryobi and Harbor Freight mindset.. throttle down lol. I'll need to build the tracker anyway for a fresnel lense heater. I'd like to nail a focused beam into a very thick steel block, holes drilled and tapped for a hydronic heating core. So many ideas... ?

 

[Hedges]

Definitely want to build a DIY solar tracker. I know more panels will solve the loss, though using something at 60% contradicts my Ryobi and Harbor Freight mindset.

Trackers for PV panels hardly made sense 15+ years ago when I paid $4 to $5/watt for panels. Same capital cost per watt as adding panels but shorter lifespan.
Today with PV panels available for $0.15 to $0.50/watt the tradeoff isn't even worth considering.

If you parallel panels with multiple orientations you get passive "tracking".
I figure two panels 90 degrees (6 hours) different orientation peaks at 0.7x the current they would aimed the same direction.
At 60 degree angle (or 120 degree depending on which direction you measure), peaks at 0.5x, i.e. max current is no greater than a single panel.
I'm considering doing that with 5' tall panels on my truck roofrack. Folded flat, only one is exposed. Tilted up they form an equilateral triangle. With that triangle tilted South (for non-summer months) they should produce relatively constant power all day long.

Sun lower in the sky of course is more attenuated, also reflection off glass varies with angle of incidence.

 

[ArthurEld]

I built our house with steel stud structure/styrofoam SIP.

Exterior walls are about 9 inches thick and the ceiling about 14 inches thick.

Exterior covered with OSB, then basic wrap. The OSB was to make it easier to vinyl side without having to find the steel studs. Conventional roof. Drywall interior.

We face the water on the south side of the house and have a considerable amount of windows there.

On a sunny day in February I will turn off the heat first thing in the morning and the house will passively heat well into the 70’s fahrenheit while it is single digit temperatures outside.

I expect the house will outlive me by a considerable margin ?

That sounds like an interesting house.

 

[Pickuptrck]

Trackers for PV panels hardly made sense 15+ years ago when I paid $4 to $5/watt for panels. Same capital cost per watt as adding panels but shorter lifespan.
Today with PV panels available for $0.15 to $0.50/watt the tradeoff isn't even worth considering.

If you parallel panels with multiple orientations you get passive "tracking".
I figure two panels 90 degrees (6 hours) different orientation peaks at 0.7x the current they would aimed the same direction.
At 60 degree angle (or 120 degree depending on which direction you measure), peaks at 0.5x, i.e. max current is no greater than a single panel.
I'm considering doing that with 5' tall panels on my truck roofrack. Folded flat, only one is exposed. Tilted up they form an equilateral triangle. With that triangle tilted South (for non-summer months) they should produce relatively constant power all day long.

Sun lower in the sky of course is more attenuated, also reflection off glass varies with angle of incidence.

I'll heed to the experience. It does seem wasteful, but I understand the logic. I was looking at it as needing larger inverter etc, but it's more of a usage levelling/maximization it seems, level overall throughout the day with a smaller inverter and more panels.. if even not all are fully used. That's why I'm here... To learn that I don't know all that I think I do ? Thanks!

 

[Pickuptrck]

What voltage should be placed in block K10? Battery voltage of 48, or inverter split phase combined 240? The figures vary wildly with changes. I'll post everything once that's settled.